.\"	$OpenBSD: panic.9,v 1.9 2014/07/13 23:03:03 schwarze Exp $
.\"     $NetBSD: panic.9,v 1.2 1996/10/09 17:20:04 explorer Exp $
.\"
.\" Copyright (c) 1996 Michael Graff.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"      This product includes software developed by Michael Graff
.\"      for the NetBSD Project.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
.\"
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.\"
.Dd $Mdocdate: July 13 2014 $
.Dt PANIC 9
.Os
.Sh NAME
.Nm panic
.Nd Bring down system on fatal error
.Sh SYNOPSIS
.In sys/types.h
.In sys/systm.h
.Ft void
.Fn panic "const char *fmt" ...
.Sh DESCRIPTION
The
.Fn panic
function makes the
.Ox
system terminate.
The message
.Fa fmt
is a
.Xr printf 9
style format string.
The message is printed to the console and the location
pointed to by the global char pointer
.Fa panicstr
is set to the address of the message text for retrieval from the OS
core dump.
.Pp
If the kernel debugger is installed, control is passed to it.
Otherwise, an attempt is made to save a core dump of the OS to a configured
dump device.
.Pp
If
.Fn panic
is called twice (from the disk sync routines, for example) the system is
rebooted without syncing the disks.
.Sh RETURN VALUES
The
.Fn panic
function does not return.
.Sh SEE ALSO
.Xr printf 3 ,
.Xr boot 9 ,
.Xr printf 9
